LAUSR

Alignment of carbon nanotubes (CNT) is of great importance for the fabrication of high-speed electronic devices such as a transistor as the electron mobilities can be greatly enhanced with aligned CNT architectures. Here, we report, for the first time, a methodology to obtain preferentially aligned CNT traces on flexible polyimide substrate utilizing high-resolution aerosol jet printing technique and evaporation-driven self-assembly process. Self-assembled twin-line of CNT ("coffee ring" effect) is observed in the deposit patterns and the field-emission scanning electron microscopy (FESEM) images reveal that highly self-ordered CNT in the resulting CNT twin-line. Various aerosol jet parameters have been investigated to obtain printed tracks in the range of 30-80 µm and conductive tracks (single CNT twin-line width) in the range of 600-1500 nm. The smallest CNT twin line obtained in this experiment is found to be approximately 16 µm by using suitable sheath-to-atomizer flow ratio. Image analysis of FESEM images confirms the formation of aligned CNT traces at the ink periphery. The effect of the line width on the degree of alignment of the CNT is studied and evaluated. The electrical resistance of the CNT trace is adjustable by controlling the number of print passes and print speed.